The Synergistic Effect Of Ann Gro On Sethoxydim And Its Influence On The Safety Of Foxtail Millet

There are many kinds of weeds in foxtail millet field,which seriously reduce the yield of foxtail millet and affect the quality of foxtail millet.Chemical weeding technology in foxtail millet field can not be popularized and applied because of less varieties of herbicides and immature application technology.Manual weeding is labor-consuming,time-consuming,low efficiency and high labor intensity.Weed damage has become an important limiting factor restricting the development of foxtail millet industrialization.Sethoxydim is mostly used in zhangzagu,Jigu and other hybrid foxtail millet fields.Conventional foxtail millet is sensitive to sethoxydim and can not be used because of its serious damage after application.Ann Gro has the characteristics of improving the efficacy and safety of herbicides.In this study,different concentrations of sethoxydim were mixed with Ann Gro,in order to explore the synergistic effect of Ann Gro on sethoxydim and the safety of foxtail millet.The main results showed that:1.The effect of the mixed use of Ann Gro and sethoxydim on the control effect of weeds.After the mixture of sethoxydim and Ann Gro,it could promote the effect of sethoxydim,accelerated the occurrence of eleusine indica drug damage symptoms and deepen the degree of drug damage,and had a good effect on the control of eleusine indica.Under the treatment of the same dose of sethoxydim,with the addition of 45.0 mL·hm^-2 of Ann Gro,the occurrence of phytotoxicity occurred 0 to 1 day earlier;added90.0,180.0 mL·hm^-2 of Ann Gro,the time of phytotoxicity appears 1² days earlier;after mixed use of sethoxydim and Ann Gro,it was 0¹ grade higher than that of single used of sethoxydim at the same dose;with the increase of the dosage of Ann Gro,the time of appearance of the phytotoxicity symptoms,phytotoxicity level,fresh weight control effect,and plant control effect of eleusine indica would increase accordingly;ED₅₀ and ED₉₀ values would decrease accordingly.Adding 180.0 ml·hm^-2 of Ann Gro had the best effect on promoting the efficacy of sethoxydim,ED₅₀ value decreased by 81.1 ml·hm^-2,efficiency increased by 21.10%;ED₉₀ value decreased by 1087.1 ml·hm^-2,efficiency increased by 51.06%.2.The effect of Ann Gro on agronomic characters and photosynthetic physiological indexes of foxtail millet under the stress of sethoxydim.With the increase of sethoxydim dosage,the agronomic traits,photosynthetic pigment content,net photosynthetic rate,activity of photosystem reaction center and target enzyme activity of Jingu 21 and Zhangza 10 decreased gradually,while antioxidant enzyme activity,soluble protein content and malondialdehyde content increased gradually.On the 30 th day after spraying 187.5 ml·hm^-2 sethoxydim,most of the indexes of Jingu 21 seedlings were significantly lower than those of the control,while the indexes of Zhangza 10 seedlings were not significantly lower than those of the control when spraying1500.0 ml·hm^-2 sethoxydim.Ann Gro could promote the growth and development of millet,with the increase of the dose of Ann Gro,the promoting effect first increased and then decreased.When the dose of Ann Gro was 180.0 ml·hm^-2,the growth and development of millet was the best.After adding different doses of Ann Gro to the same dose of sethoxydim,the results showed that plant height,leaf area,photosynthetic pigment content（Chla、Chlb、Car、Chl（a+b））,net photosynthetic rate（P_n）,stomatal conductance（G_s）,transpiration rate（T_r）,effective photochemical quantum yield of PSⅡ（Y（Ⅱ））,electron transfer rate（ETR）,photochemical quenching coefficient（qP）,antioxidant enzyme activity（SOD、POD、CAT）and target enzyme（acetyl Co A carboxylase）content of foxtail millet increased at first and then decreased,and reached the maximum at 180.0 ml·hm^-2;intercellular CO₂ concentration（C_i）,non photochemical quenching coefficient（NPQ）,soluble protein content and malondialdehyde（MDA）content decreased at first and then increased,and reached the minimum at 180.0 ml hm^-2.The results showed that 180.0 ml hm^-2 of Ann Gro had the best effect on alleviating the damage of sethoxydim.Part of the reasons for the alleviation of herbicide damage by Ann Gro may be through increasing net photosynthetic rate,photosynthetic pigment content,increasing PSⅡ activity and antioxidant enzyme activity,reducing soluble protein content and malondialdehyde content,so as to improve the resistance of foxtail millet to herbicide.In summary,the mixed use of Ann Gro and sethoxydim could improve the efficacy of herbicides,and to a certain extent alleviate the phytotoxicity of the herbicides.